In order to saving thermal energy, latent heat thermal energy storage systems (LHTESS) can be utilized. Common phase change material (PCM) has low thermal conductivity. In this paper, CuO nanoparticles have been used to enhance the performance of LHTESS. CuO–water nanofluid properties are estimated by means of KKL. This unsteady process has been simulated by Finite element method. Results prove that solidification process is accelerated by adding CuO nanoparticles in to pure PCM. As number of undulations increases average temperature and total energy profiles reduce while solid fraction profile increases. Also, it can be concluded that highest rate of solidification is obtained for dp = 40 nm.

Numerical simulation for solidification in a LHTESS by means of nano-enhanced PCM

Improving heat transfer is a critical subject for energy conservation systems which directly affects economic efficiency of these systems. There are active and passive methods which can be employed to enhance the rate of heat transfer without reducing the general efficiency of the energy conservation systems. Among these methods, passive techniques are more cost-effective and reliable in comparison with active ones as they have no moving parts. To achieve further improvements in heat transfer performances, some researchers combined passive techniques. This article performs a review of the literature on the area of heat transfer improvement employing a combination of nanofluid and inserts. Inserts are baffles, twisted tape, vortex generators, and wire coil inserts. The progress made and the current challenges for each combined system are discussed, and some conclusions and suggestions are made for future research.

Combination of nanofluid and inserts for heat transfer enhancement

https://www.tandfonline.com/doi/pdf/10.1080/16583655.2018.1483795

Effects of MHD and slip on heat transfer boundary layer flow over a moving plate based on specific entropy generation

Convective heat transfer flow of nanofluid in a porous medium over wavy surface

Water/MWCNT nanofluid based cooling system of PVT: Experimental and numerical research

Volume of fluid model to simulate the nanofluid flow and entropy generation in a single slope solar still

This paper performs an entropy generation analysis for nanofluid turbulent flow around a rotating cylinder. A finite volume method based on SST k–ω turbulence model is employed to solve the governing equations and calculate the viscous and thermal entropy generations. The effects of different parameters containing the non-dimensional rotation rate, nanoparticle concentration, and Reynolds number on the viscous and thermal entropy generations and Bejan number are investigated. The obtained results indicate that there is an optimal non-dimensional rotation ratio at α = 1.5 as it has the minimal viscous entropy generation among other values of α. The viscous entropy generation seems to be enveloped around the cylinder. Finally, the viscous entropy generation is dominant in most of the domain except at the regions with an upward drift and a thin layer around the cylinder wall.

Second law of thermodynamic analysis for nanofluid turbulent flow around a rotating cylinder

Thermo-hydraulic analysis for a novel eccentric helical screw tape insert in a three dimensional tube

A numerical investigation of magnetic field effect on blood flow as biomagnetic fluid in a bend vessel

This paper presents numerically an appropriate position of a porous insert to get a better thermohydraulic performance from a porous heat exchanger The simulation is based on the Darcy-Brinkman-Forchheimer model in the porous field Two-dimensional continuity, momentum, and energy equations with incompressible, laminar, steady assumptions have been solved using a finite volume approach The analysis is performed for different values of porous layer thickness, length, and porosity at a fixed value of Reynolds number (Re = 100) and thermal conductivity ratio (Rc = 5) The results showed that there is about a 48% and 13% reduction in pressure drop and Nusselt number, respectively, by decreasing horizontal porous substrate thickness from 1 to 1/2 for δv = 1/3 at e = 07 As a result, the pressure drop reduces considerably with a reasonable reduction in heat transfer rate by decreasing horizontal porous substrate thickness from 1 to 1/2

Shima Akar

Papers

Volume of fluid model to simulate the nanofluid flow and entropy generation in a single slope solar still

Second law of thermodynamic analysis for nanofluid turbulent flow around a rotating cylinder

Thermo-hydraulic analysis for a novel eccentric helical screw tape insert in a three dimensional tube

A numerical investigation of magnetic field effect on blood flow as biomagnetic fluid in a bend vessel

Appropriate position of porous insert in a heat exchanger by thermohydraulic analysis